The highest-security stop on Bush's five-nation tour, the Sunday visit to Colombia was also the shortest stopover on the trip.

The protesters object to the US$700 million (EUR 532 million) annually received by Colombia in mostly military U.S. aid, blaming the assistance for fueling the country's decades-old civil conflict and encouraging human rights abuses by this country's armed forces. The demonstrators also protested the U.S. war in Iraq.

As Bush arrived in Guatemala on Sunday night, more than 100 Mayan Indians protested in the city of Tecpan, holding signs that read: "No more blood for oil."

The group is angry that Bush will be visiting the sacred Iximche archaeological site. After the U.S. leader leaves, Mayan priests plan a spiritual cleansing to get rid of the "evil spirits" they believe Bush will bring.

"He's someone who has financed the genocide of many parts of the works, like in the Middle East," protester Jorge Morales said.

Iximche, 30 miles (50 kilometers) west of the capital of Guatemala City, was founded as the capital of the Kaqchiqueles kingdom before the Spanish conquest in 1524.

For Bush's visit to Colombia, some 200 helmeted police in full body armor responded to protests with water cannon and tear gas and reclaimed the street - about a mile (1.6 kilometers) from the presidential palace where the U.S. president got a red-carpet welcome - banging batons against riot shields as they marched forward.

Some of the rioters, mainly students, later rampaged down Bogota's main avenue, breaking shop windows and ripping computers from bank offices. The rioters had broken away from a larger group of 2,000 protesters.

Four police officers were injured and 100 people were arrested, said Bogota police chief Gen. Daniel Castiblanco.

A small bomb exploded Sunday morning in the lawless Pacific port of Buenaventura, injuring two civilians. The police blamed the Revolutionary Armed Forces of Colombia, or FARC, which has been fighting the government for 42 years but which President Alvaro Uribe has put on the defensive, the AP said.

Security in Bogota was extensive, with some 7,000 police and troops blocked off large parts of the Colombian capital, while 14,000 reinforcements set up roadblocks, checking IDs and searching vehicles.

In contrast with visits to Bogota by U.S. presidents Ronald Reagan in 1982 and John F. Kennedy in 1961, there was no popular reception for Bush, with streets adjacent the presidential palace closed to traffic and pedestrians alike.